Air separator fitting for hydronic systems



Jan. 22, 1963 L. E. MAIN 3,074,645

AIR SEPARATOR FITTING FOR HYDRONIC SYSTEMS Filed NOV. 21, 1960 Inventor Leo E. Main 3 Jlaww, $0010 a: f-H-fornegs United States Patent ()fifice 3,fi74,645 Patented Jan. 22, 1963 3,074,645 AIR SEPPARATOR FHTTZNG FUR HYDRQNKC SYSTEMS Leo E. Main, Chicago, ill, assignor to Bell Gossett fiornpany, a corporation of Illinois Filed Nov. 21, 1960, Ser. No. 79,697 Claims. (Cl. 237-63) This invention relates to improvements in a novel tank type fitting for use in separating entrained air from a fluid flowing in a hydronic heating or cooling system and more particularly it is concerned with an improved bidirectional flow regulating and air separating element for use in a tank type fitting for universal installation in all types of heat exchangers and boilers. For this purpose it has inlet and outlet openings arranged to accommodate connection to either side outlet or top outlet arrangements.

It is well known that as a flowing stream of water is heated air bubbles become entrained in the stream and are carried with it through the piping and radiation gear of a hydronic system. These entrained air bubbles cause gurgling noises throughout the system and in many instances become lodged in parts of the radiation gear so as to interfere with or actually prevent the desired circulation through the system. Various facilities are known for separating these entrained air bubbles from the main stream of the fluid circuit and collecting and depositing the air bubbles in a compression tank that is provided for the system. Prior to the present invention the facilities for side outlet and top outlet boiler arrangements have been distinctively different due to the varying fluid connection and air separation problems that are involved. Moreover, the present day facilities have been unduly expensive in many instances and have required special piping and other auxiliary fittings to facilitate their incorporation into a system and in other instances have been dimcult to locate.

The provision of a bidirectional fiow regulating and air separating element in a tank type air separator fitting of compact -cost construction suitable for universal application to both side outlet and top outlet types of boilers is the principal object of this invention.

A more specific object of the invention is the provision of such a bidirectional element within the bottom end of a fitting of the above type to accommodate either upfeed or downfeed radiation circuits or both in the case of multiple zone systems.

Other objects and advantages of this invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a vertical sectional view through a novel air separator fitting equipped with a bidirectional flow regulating element in accordance with this invention;

FIG. 2 is a top plan view of the fitting with parts broken away and sectioned to facilitate disclosure;

FIG. 3 is a fragmentary diagrammatic illustration of a hot water heating system having a side outlet type boiler that is shown equipped with an air separator fitting constructed in accordance with this invention and connected to provide a multiple zone circulation system having both upfeed and downfeed circuits; and

FIG. 4 is a fragmentary diagrammatic illustration of a hot water heating system having a top outlet type boiler that is shown equipped with the identical air separator fitting connected in an upfeed circulation system.

Referring now to the drawings, in its preferred form the invention is embodied in an air separator fitting, such as is illustrated in FIGS. 1 and 2. The fitting comprises a vertically elongated hollow tank 10 having generally elliptically shaped surrounding side wall structures 10S and correspondingly shaped top and bottom walls NT and 10B, respectively, enclosing and defining an air separation chamber 11 of substantially greater flow capacity than the piping of the liquid flow circuit in which it is used.

A water outlet or port opening 12 and an air outlet opening 13 are provided in the top wall adjacent its opposite extremities with a dip tube 14 being fitted permanently within the liquid outlet and projecting to a point adjacent the bottom wall of the fitting. The dip tube thus provides a separate flow chamber or conduit located within the confines of the main separator chamber 11, and the lower end of the dip tube is open and is cut on a bias to more efficiently receive the air free liquid pooling in the bottom of the chamber for discharge through the top outlet.

An opening or port 15 is provided adjacent the top and approximately centrally of one of the major side wall sections to provide an inlet port for convenient connection to a side outlet type boiler arrangement. As fluid enters the port 15 from a side inlet pipe connection, it jets across the separation chamber at high velocity to strike the opposite major side wall section and deflect for directing the fluid stream toward the bottom of the tank at a greatly reduced velocity. This reduction in velocity of the entering liquid permits the entrained air to separate from the moving stream, whereupon the air rises to the top of the tank for delivery through the air outlet port 13. The air-free fluid collecting in the bottom of the tank is continuously drawn up the dip tube to exit through the liquid outlet port 12.

The pertinent elements of a forced hot water heating system, as shown in FIG. 3, include a side outlet type boiler 20, the fitting 10 of this invention mounted alongside the boiler and connected through a conduit, not shown, which leads into its side inlet port 15 to deliver a stream of water entrained with air bubbles, and a booster pump 21 having its suction side connected to the top outlet port 12 by a conduit 22 and having its discharge side connected through supply piping 23 leading to the radiation gear, with the piping 24 constituting a re turn line from the radiation gear and feeding into the bottom of the boiler. A conventional compression tank 25 is connected through a line of piping 26 to the air outlet port 13 for receiving and storing the air that is separated out by the fitting 10. A cold water supply line 27 is shown tapped into the piping 26 and includes a control valve 28 for initially filling the system.

An opening or port 16 is provided through the bottom wall 103 of the tank at an extremity thereof adjacent to the end of the top wall at which the air outlet port 13 is located and flow through this port is bidirectional in that in some applications of the fitting air-free liquid emerges from the tank through this port and in other applications liquid entrained with air enters the tank for separation of the air in the tank.

When the fitting is used on a side outlet boiler arrangement such as is shown in FIG. 3, it may be required that the lair-free liquid be withdrawn from the port 16 of the bottom wall rather than through the dip tube. A circulation system of this type is also shown in FIG. 3 wherein, for the moment, it may be assumed that the outlet port 12' of the dip tube is plugged up. A separate radiation system is shown having piping 29 connected to extend from the bottom port 16 of the fitting 10 to the suction side of a booster pump 30, the discharge side of which is connected to piping 31 that feeds radiation gear, not shown, with the return line 24 being assumed to be connected to the other side of this system.

FIG. 3 may also be viewed as an illustration of a multiple zone radiation system having one radiation circuit that includes the booster pump 21 being supplied with air free liquid from the dip tube 14 and outlet port 12 and having a separate radiation circuit that includes the booster pump 30 being supplied with air-free liquid through the bottom outlet port 16. An added advantage of the fitting of this invention is that it is conveniently adaptable to the connection arrangements for such a multiple zone system and moreover it maintains its etficiency even in such a multiple zone system. For such an application the air separating action in the tank 14) is substantially identical, since in both instances the air-free liquid is drawn out from a point closely adjacent the bottom of the tank. Alternatively, in a multiple zone radiation system liquid may be drawn simultaneously through both the dip tube 14 and the bottom port 16.

In accordance with this invention, the multiple purpose fitting is equipped with a special flow reducing element 17 mounted in and forming an internal passage extension of the bottom port 16. The flow reducing element is of tubular form and projects almost half way up the separator chamber 11 to terminate in an end wall 18. The lengthwise walls of the element 17 have a multiplicity of openings 19 closely spaced axially and circumferentially thereabout and opening in substantially all radial directions to establish communication between the separator chamber and the interior of the flow reducing element. Thus the element 17 may be described as a perforated basket.

In the application of the fitting illustrated in FIG. 3, the part of the liquid entering the side inlet port 15 which is destined to flow outwardly through the bottom port 16 first strikes the opposing main side wall section of the tank and as described previously is then directed toward the bottom of the separation chamber at a reduced velocity. This liquid then enters the perforated basket 17 during which its velocity is even further reduced allowing more of the entrained air to rise to the top of the fitting and thence to the compression tank. Thus the flow reducing element acts to importantly increase the air separation efficiency of the fiting in down feed circulation systems.

The other function of the bottom port 16 of the fitting relates to the use of the fitting with top outlet type boiler arrangements such, for example, as is shown in FIG. 4 in which case the port of the side wall is plugged up. The liquid entrained with air issues from the boiler 20 and enters through the bottom port 16 and air free liquid is drawn ofi through the dip tube. As the air entrained liquid enters at the bottom of the fitting and flows into the enlarged air separation chamber 11, its velocity of flow must be reduced sufficiently to permit air bubbles to separate out from the liquid, whereupon the [air bubbles again rise to the top of the separation chamber for delivery to the compression tank 25. This action is, in general, similar to that described previously, and a radiation system is shown in FIGURE 4 wherein the fitting 10 is mounted directly above the boiler 29 that is illustrated as being of the top outlet type, with piping 20F connecting the liquid being discharged from the boiler into the bottom port of the fitting. Air-free liquid is drawn off through the piping 22 by a booster pump 21 which circulates the air-free liquid throughout the system. The compression tank 25 is connected through the piping 26 to the air outlet port 13 and a water supply line 27 having a valve 28 is again shown tapped into the piping 26.

At the flow rates utilized in many of the present day forced liquid circulation systems, the upwardly moving stream entering the bottom port 16 of the fitting, in its application in a system such as is shown in FIG. 4 and in the absence of the element 17, can create a jet effect within the separation chamber and set up a swirling and highly turbulent liquid pattern that inhibits separation and elimination of air.

The perforated tubular element has proven to be particularly effective in breaking up this jet eiiect and in achieving a substantially higher air separation efiici-ency. For example, tests have shown that with a liquid stream entering upwardly through the port 16, the efiiciency of air separation is increased by 33% where a perforated basket 17 is employed as compared with a comparable arrangement where no such basket is employed. The element 17 acts to convert the entering liquid stream into a multiplicity of differently directed low velocity streams which totally eliminate the jet efiect within the fitting and, more importantly, which encourage a highly efiicient separation of the entrained air.

It should be noted that the provision of the usual type of internal baffle within the tank for redirecting or deflecting the liquid stream entering through port 16 does not actually break up the jet eifect and hence does not improve the air separation efficiency.

The individual holes 19' in the flow reducing element must be large enough to be free of any strainer effect since lint and other foreign materials carried in the liquid stream would gradually block the openings 19 and clog the system. To provide a sufiicient velocity reduction, the total area of the holes 13 should equal about twice the transverse cross-sectional area of the systems piping and this relationship determines the extent to which the element projects into the separator chamber.

It should be understood that the description of the preferred form of the invention is for the purpose of complying with Section 122., Title 35 of the United States Code, and that the appended claims should be construed as broadly as the prior art will permit.

I claim:

1. In a multiple purpose air separator for direct interposition in a forced circulation hydronic system of the type including a boiler of either the side outlet or top outlet type and also including a booster pump and piping connecting the boiler, the separator and the booster pump in series, and a compression tank connected for trapping air separated from liquid in said system, said separator including a tank having openings therein and providing a vvertically elongated chamber of substantially greater flow capacity than the total of said openings in said tank, said tank having surrounding side wall structure provided with an inlet opening horizontally therethrough for supplying liquid entrained with air horizontally into said chamber to impinge upon an opposing portion of said side wall structure and effect a velocity reduction of said liquid as it enters said tank to allow for separation of entrained air and a pooling of air free liquid within the lower end of said chamber, said tank having a top wall having a liquid outlet opening and an air outlet opening at opposite extremities thereof and having a dip tube in said liquid outlet opening and projecting to adjacent the lower end of said chamber for drawing air free liquid pooling within the lower end of said chamber, and said tank having a bottom wall having an opening to said chamber and optionally connectable either as a liquid outlet for communication with air free liquid pooling within the lower end of said chamber or as a liquid inlet opening into said chamber for supplying liquid entrained with air thereinto to efiect a velocity reduction of said liquid as it enters said tank and thereby allow for separation of entrained air and a pooling of air free liquid within the lower end of said chamber for exit through said dip tube, and said separator having a tubular fiow reducing element mounted in and forming an internal passage extension of said bottom wall opening, said element having an end wall in said chamber and spaced from said bottom wall opening, and said element having a multiplicity of diiferently directed transverse holes opening into the lower end of said chamber.

2. In the separator of claim 1, an arrangement wherein the composite area of said transverse holes in said element substantially exceeds the cross-sectional area of said bottom wall opening.

3. In a multiple purpose air separator for direct interposition in a forced circulation hydronic system of the type including a boiler of either the side outlet or top outlet type and also including a booster pump and piping connecting the boiler, the separator and the booster pump in series, and a compression tank connected for trapping air separated from liquid in said system, said separator including a tank having openings therein and providing a vertically elongated chamber of substantially greater flow capacity than the total of said openings in said tank, said chamber having a generally elliptical horizontal crosssectional configuration, said tank having surrounding side Wall structure provided centrally within one major wall section thereof with an inlet opening horizontally therethrough for supplying liquid entrained with air horizontally into said chamber to impinge upon an opposing major wall section of said side wall structure and effect a velocity reduction of said liquid as it enters said tank to allow for separation of entrained air and a pooling of air free liquid within the lower end of said chamber, said tank having a top wall having a liquid outlet opening and an air outlet opening at opposite extremities thereof and having a dip tube in said liquid outlet opening and projecting to adjacent the lower end of said chamber for drawing air free liquid pooling within the lower end of said chamber, and said tank having a bottom Wall having an opening to said chamber at the extremity thereof that underlies said air outlet opening and optionally connectable either as a liquid outlet for communication with air free liquid pooling within the lower end of said chamber or as a liquid inlet opening into said chamber for supplying liquid entrained with air thereinto to effect a velocity reduction of said liquid as it enters said tank and thereby allow for separation of entrained air and a pooling of air free liquid Within the lower end of said chamber for exit through said dip tube, and said separator having a straight sided perforated basket mounted vertically in and forming a vertically elongated internal passage extension of the bottom wall opening, said basket having an end wall in said chamber and spaced above said bottom wall opening and said element having a multiplicity of dilferently directed transverse holes opening into the lower end of said chamber.

4. In the separator of claim 3 wherein the transverse holes in said basket have a composite area that substantially exceeds the cross-sectional area of said bottom wall opening.

5. In a forced circulation hydronic system, the combination including a boiler of either the side outlet or top outlet type, a multiple purpose air separator, a booster pump, piping connecting the boiler, the separator and the booster pump in series, and a compression tank connected for trapping air separating from liquid in said separator, said separator comprising a tank having openings therein and providing a vertically elongated chamber of substantially greater flow capacity than the total of said openings in said tank, said tank having surrounding side wall structure provided with an inlet opening horizontally therethrough for supplying liquid entrained with air horizontally into said chamber to impinge upon an opposing portion of said side Wall structure and effect a velocity reduction of said liquid as it enters said tank to allow for separation of entrained air and a pooling of air free liquid within the lower end of said chamber, said tank having a top wall having a liquid outlet opening and an air outlet opening at opposite extremities thereof and having a dip tube in said liquid outlet opening and projecting to adjacent the lower end of said chamber for drawing air free liquid pooling within the lower end of said chamber, and said tank having a bottom wall having an opening to said chamber and optionally connectable either as a liquid outlet for communication with air free liquid pooling within the lower end of said chamber or as a liquid inlet opening into said chamber for supplying liquid entrained with air thereinto to effect a velocity reduction of said liquid as it enters said tank and thereby allow for separation of entrained air and a pooling of air free liquid within the lower end of said chamber for exit through said dip tube, and said separator having a tubular flow reducing element mounted in and forming an internal passage extension of said bottom wall opening, said element having an end wall in said chamber and spaced from said bottom wall opening, and said element having a multiplicity of differently directed transverse holes opening into the lower end of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 473,591 Reilly Apr. 26, 1892 1,849,196 Meurk et a1. Mar. 15, 1932 2,160,801 Goerg May 30, 1939 2,652,069 Gohcen Sept. 15, 1953 2,713,973 Hencken et a1. July 16, 1955 FOREIGN PATENTS 196,336 Switzerland June 1, 1938 

1. IN A MULTIPLE PURPOSE AIR SEPARATOR FOR DIRECT INTERPOSITION IN A FORCED CIRCULATION HYDRONIC SYSTEM OF THE TYPE INCLUDING A BOILER OF EITHER THE SIDE OUTLET OR TOP OUTLET TYPE AND ALSO INCLUDING A BOOSTER PUMP AND PIPING CONNECTING THE BOILER, THE SEPARATOR AND THE BOOSTER PUMP IN SERIES, AND A COMPRESSION TANK CONNECTED FOR TRAPPING AIR SEPARATED FROM LIQUID IN SAID SYSTEM, SAID SEPARATOR INCLUDING A TANK HAVING OPENINGS THEREIN AND PROVIDING A VERTICALLY ELONGATED CHAMBER OF SUBSTANTIALLY GREATER FLOW CAPACITY THAN THE TOTAL OF SAID OPENINGS IN SAID TANK, SAID TANK HAVING SURROUNDING SIDE WALL STRUCTURE PROVIDED WITH AN INLET OPENING HORIZONTALLY THERETHROUGH FOR SUPPLYING LIQUID ENTRAINED WITH AIR HORIZONTALLY INTO SAID CHAMBER TO IMPINGE UPON AN OPPOSING PORTION OF SAID SIDE WALL STRUCTURE AND EFFECT A VELOCITY REDUCTION OF SAID LIQUID AS IT ENTERS SAID TANK TO ALLOW FOR SEPARATION OF ENTRAINED AIR AND A POOLING OF AIR FREE LIQUID WITHIN THE LOWER END OF SAID CHAMBER, SAID TANK HAVING A TOP WALL HAVING A LIQUID OUTLET OPENING AND AN AIR OUTLET OPENING AT OPPOSITE EXTREMITIES THEREOF AND HAVING A DIP TUBE IN SAID LIQUID OUTLET OPENING AND PROJECTING TO ADJACENT THE LOWER END OF SAID CHAMBER FOR DRAWING AIR FREE LIQUID POOLING WITHIN THE LOWER END OF SAID CHAMBER, AND SAID TANK HAVING A BOTTOM WALL HAVING AN OPENING TO SAID CHAMBER AND OPTIONALLY CONNECTABLE EITHER AS A LIQUID OUTLET FOR COMMUNICATION WITH AIR FREE LIQUID POOLING WITHIN THE LOWER END OF SAID CHAMBER OR AS A LIQUID INLET OPENING INTO SAID CHAMBER FOR SUPPLYING LIQUID ENTRAINED WITH AIR THEREINTO TO EFFECT A VELOCITY REDUCTION OF SAID LIQUID AS IT ENTERS SAID TANK AND THEREBY ALLOW FOR SEPARATION OF ENTRAINED AIR AND A POOLING OF AIR FREE LIQUID WITHIN THE LOWER END OF SAID CHAMBER FOR EXIT THROUGH SAID DIP TUBE, AND SAID SEPARATOR HAVING A TUBULAR FLOW REDUCING ELEMENT MOUNTED IN AND FORMING AN INTERNAL PASSAGE EXTENSION OF SAID BOTTOM WALL OPENING, SAID ELEMENT HAVING AN END WALL IN SAID CHAMBER AND SPACED FROM SAID BOTTOM WALL OPENING, AND SAID ELEMENT HAVING A MULTIPLICITY OF DIFFERENTLY DIRECTED TRANSVERSE HOLES OPENING INTO THE LOWER END OF SAID CHAMBER. 